In 2010 approximately 370,000 children were newly infected with HIV worldwide as a result of mother-to-child transmission (MTCT). Over 90% of these infections occurred in South Africa. HIV represents the main cause of maternal mortality in South Africa and accounts for over 50% of deaths in children under 5 years old. Exclusive breastfeeding (EBF) has been identified as a key intervention to reduce MTCT of HIV and improve infant health. Although breastfeeding by HIV+ mothers carries a risk of HIV transmission from mother-to-child, that risk decreases from 42% to 2% with the practice of EBF and appropriate antiretroviral therapy. The mechanism by which EBF is associated with lower MTCT is not fully understood, but believed to maintain the gastrointestinal barrier, which is thought to be the primary site of infection. The multiple benefits of EBF in protecting infants fro MTCT of HIV and providing optimal nutrition while protecting them against diarrheal and respiratory illness compared to other feeding methods are significant. Given the overwhelming evidence illustrating these benefits, in 2010 the World Health Organization updated their infant feeding guidelines to recommend in limited-resource settings HIV+ mothers engage in EBF for the first 6 months of their infant's life. However, despite increased resources devoted to promoting EBF within prevention of MTCT of HIV programs, it remains a rare practice. In South Africa, 76% of HIV+ mothers feed their infants a combination of breast milk, cow milk and porridge by 3 months, and approximately 25% introduce water within the first 3 days of the infant's life. Using the Information, Motivation, and Behavioral Skills (IMB) model of health behavior change as the theoretical and conceptual framework, the proposed study aims to change prevalent non-EBF practice through a well-targeted IMB-model based intervention. The IMB model is applied to elicit the most prominent IMB barriers inhibiting mothers living with HIV from practicing EBF and using this data to inform the design of an IMB-model based intervention to enhance those IMB determinants influencing EBF behavior using motivational interviewing techniques. Rigorous evaluation will occur to evaluate the efficacy of the intervention on EBF-relevant information, motivation, behavioral skills determinants, and EBF practice at 6 weeks follow-up. The proposed study contributes an innovative and practical approach to help eliminate MTCT of HIV through utilizing a well-established and empirically proven model that has been successfully implemented to eliminate other types of HIV risky behavior in South Africa. A contribution that constitutes a critical step in meeting the 2011-2015 Millennium Development Goals established by the United Nations General Assembly Special Session.